For detailed information about the amounts and types of (a) sex and nudity, (b) violence and gore, (c) profanity, (d) alcohol, drugs, and smoking, and (e) frightening and intense scenes in this movie, consult the IMDb Parents Guide for this movie. The Parents Guide for Pacific Rim can be found here.

Twelve years after the opening of a breach under the Pacific Ocean has allowed giant, reptilian creatures called Kaiju to emerge from another dimension, the attacks of the Kaiju have escalated and the army of massive robots called Jaegers built to fight them have proven unsuccessful. In a desperate attempt to save mankind, the head of the Jaeger program Stacker Pentecost (Idris Elba) decides to reactivate four Jaegers and summons former Jaeger pilot Raleigh Becket (Charlie Hunnam) to pilot the Gipsy Danger. Because of the massive size of the Jaegers, however, they require two compatible pilots with their minds neurally interlocked, referred to as "drifting", in order to control the robots. After sparring with Pentecost's adopted daughter Mako Mori (Rinko Kikuchi), Becket decides that he wants to "drift" with her, but Pentecost refuses. Meanwhile, the Kaiju attacks continue to intensify.

It's explained in the film, and further in the prequel comic, that the neural strain of controlling a 250-foot-tall robot is just too much for one person to handle. Each pilot controls one side of the robot, left or right, similar to how humans use their brain hemispheres to control each side of their bodies. For more information, view Guillermo del Toro explaining it here. It could also be because of the intense concentration required to control the Jaegers: if one pilot loses focus, the other pilot can take over for a period of time. Even though not factual, it also adds a story element of team work to add some complexity to the human factor of the Jaegers and adds some additional story elements regarding the mind melding of two people. After all, much of the core of the story is about humanity working together to overcome a seemingly impossible problem, so this is a good way to illustrate that theme.

The kaiju started getting bigger and attacking more often. Apparently, the early successes were on Class 1 and 2 kaiju. As stated in the film, the kaiju class system was based on the size and mass of the kaiju. Class 3 and higher kaiju were apparently more powerful than the existing jaeger technology. Also, every kaiju win meant dead jaeger pilots, and they were more difficult to replace than the jaegers. Also, at one point, it did appear that multiple jaegers were used at one time. Raleigh refers to "standard, two jaeger battle formation" during the final battle, but all the fights shown except one only had one jaeger. This more likely refers to a lack of pilots than a lack of jaegers. The alien species that created the kaiju quite obviously was learning from the battles they lost so they began to engineer larger and more aggressive monsters that had new physical features the jaeger teams wouldn't be expecting. The "knife-head" kaiju that Raleigh and his brother fight at the beginning of the movie seemed to be designed to stab a jaeger with its forehead, a body part specifically created for that purpose. The tail of the kaiju that destroys the Crimson Typhoon was designed to grab the head of the jaeger and crush it, killing the team. Also, it is mentioned that all Kaiju's brains are connected, so other Kaiju can watch how the Jaeger fight and learn/evolve to destroy them more effectively.

It's difficult to see what happens to Yancy (Diego Klattenhoff), Raleigh's brother and drifting partner, when he's torn from the control module, but it looks like the kaiju got hold of Yancy's pilot harness and yanked him out that way. From that point, Yancy was likely thrown aside or dropped by the kaiju or simply slid off the kaiju's claw. If that had happened, he'd have fallen to his death in the water since a drop from that height is deadly, even on water. However, that is a convention in big-budget movies that is often cheated. For the purposes of the story here, Yancy is most likely dead. Raleigh was able to survive the crash landing because he was still attached to his control harness.

Dropping a nuclear bomb in the middle of a large city would be an absolute last resort, as this would easily cause as much if not more damage than a giant, rampaging monster. Plus the contamination from the fallout would be catastrophic and unpredictable, not only in the immediate blast zone but also to the rest of the world with nuclear fallout spreading according to climate and wind patterns. In the prequel comic, it is explained that the first four kaiju to attack were, in fact, destroyed with nuclear weapons. The fourth kaiju, "Scissure", which attacked Sydney, apparently took several days to lure out to sea where it could be safely nuked without decimating and contaminating all of Sydney along with it. It is precisely for this reason that the Jaeger program was developed because, if humanity had to continue to drop nukes every time a kaiju showed up, that would wipe out the human race all on its own, not to mention the catastrophic damage to Earth itself. Guillermo del Toro has stated that he does not intend Pacific Rim to be a "realistic" depiction of a giant monster invasion. Rather he intends the film to be a "beautiful poem to giant monsters"; that is, a stylized throwback to the giant monster genre. Also, as explained in the film, conventional weapons caused the kaiju's blood to contaminate the environment, a condition known as "kaiju blue."

Crimson Typhoon and Cherno Alpha (and to some extent the Striker Eureka,) faced off against the two kaiju and were surprised by the monsters' larger size, more aggressive nature, and new tactics. Also, it appears that the kaiju had a lot of experience vs these jaegers and that these particular kaiju were designed just to defeat them. This was also the first time any jaegers had fought two kaiju at the same time (remember how Geizler and Gottlieb talked emphatically about the double and triple events?), which is what caused Cherno Alpha's defeat. The flying kaiju's tail seemed to be designed to destroy the heads of jaegers, which easily killed the Crimson Typhoon team. Once these new features were used, however, the surprise factor was eliminated, and Gipsy Danger was able to anticipate and counter them. Additionally, Gipsy Danger had new features that the kaiju were unaware of, in particular the chain sword, so Gipsy also had the element of surprise.

This is a little hard to answer for sure, because we don't know the extent of the damage or disrepair that other Jaegers might have suffered. It could be that they always meant or hoped to repair other Jaegers, and that Gipsy Danger was simply the first of hopefully many, but they simply ran out of time, resources and money (remember that the PPDC has their funding cut at the beginning). It could be that Gipsy Danger was simply the one in the best condition or was the one that they felt they could most reliably repair with what they had. Or it could be that Stacker Pentecost chose Gipsy Danger because he knew that Raleigh was still out there, and he hoped that he could find Raleigh and bring him back to pilot a repaired Gipsy Danger. Some dialogue in the film seems to indicate this being a strong possibility. Gypsy Danger was the only nuclear powered Jaeger left. As such, fuel was easier to acquire to power it. Also, as explained in the film, there were newer generations of jaegers. Striker Eureka, the Australian jaeger, was "the first and last of the class 5 jaegers." Gipsy Danger was a class 3. Pentecost piloted a class 1. Mako was a specialist in Class 3 jaegers, which is why Gipsy was repaired/refitted. Older jaegers simply did not have the parts and/or tech to be repaired. In the film, they also went through great pains to explain that the Chinese and Russian jaegers were undefeated and thus did not need repairs.

There are two possibilities: Hannibal Chau (Ron Perlman) theorizes that the baby wasn't fully grown before escaping its mother. One of the biggest dangers facing any infant born prematurely is that its lungs and other organs aren't fully grown and it won't be able to breathe on its own. The other theory, which is more prominently shown in the film, is that it strangled on its own umbilical cord. An umbilical cord wrapped around the throat of an infant, called a "prolapsed" cord, is a serious danger to an infant just coming out of its mother's womb.

It was an electromagnetic pulse designed to short out and disable electronics. It's an occurrence that precedes the detonation of a large-scale nuclear weapon—the pulse is emitted moments before the detonation and disrupts anything with an electrical or electronic operating system.

The Gypsy Danger kills the remaining Kaiju and rides its body through the breach. With their oxygen levels dropping, Raleigh gives Mako his remaining oxygen and ejects her escape pod. He then overloads the Jaeger's nuclear reactor, turning it into a bomb, and then ejects himself. The Haeger explodes, sealing the breach into the alien dimension, Mako's escape pod rises to the ocean surface but Raleigh's pod is nowhere to be seen. Suddenly, it pops out on the surface. Mako swims over to help him, eventually bringing him back to consciousness. As the two hug each other, dozens of rescue helicopters fly over them. In a midcredits scene, Hannibal is seen cutting his way out of the dead infant kaiju. "Where is my goddamn shoe?", he bellows.

After the main credits, there is a short scene of Hannibal Chau slicing open the body of the kaiju that swallowed him, popping his head out, and exclaiming, "Where is my goddamn shoe?!" At the very end of the credits, it also has a special message, dedicating the film to the memory of both Ray Harryhausen (special effects pioneer for classics such as The Beast From 20,000 Fathoms, Jason and the Argonauts, the original Clash of the Titans and many more) and Ishiro Honda (director of the original Godzilla, as well as many of its sequels and other Japanese genre films, many of which inspired Pacific Rim and its source material).

Pacific Rim's live-action elements were shot in 2D and converted, but the extensive CGI shots (including essentially all of the Jaeger v. Kaiju action) were rendered in native 3D and thus were not converted.